/*
 * Copyright (c) 2006, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.tools.javac.api;

import javax.lang.model.element.Element;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.TypeElement;

import com.sun.tools.javac.comp.AttrContext;
import com.sun.tools.javac.comp.Env;

/**
 * Provides an implementation of Scope.
 * 
 * <p>
 * <b>This is NOT part of any supported API. If you write code that depends on
 * this, you do so at your own risk. This code and its internal interfaces are
 * subject to change or deletion without notice.</b>
 * </p>
 * 
 * @author Jonathan Gibbons;
 */
public class JavacScope implements com.sun.source.tree.Scope {
	protected final Env<AttrContext> env;

	/** Creates a new instance of JavacScope */
	JavacScope(Env<AttrContext> env) {
		env.getClass(); // null-check
		this.env = env;
	}

	public JavacScope getEnclosingScope() {
		if (env.outer != null && env.outer != env)
			return new JavacScope(env.outer);
		else {
			// synthesize an outermost "star-import" scope
			return new JavacScope(env) {
				public boolean isStarImportScope() {
					return true;
				}

				public JavacScope getEnclosingScope() {
					return null;
				}

				public Iterable<? extends Element> getLocalElements() {
					return env.toplevel.starImportScope.getElements();
				}
			};
		}
	}

	public TypeElement getEnclosingClass() {
		// hide the dummy class that javac uses to enclose the top level
		// declarations
		return (env.outer == null || env.outer == env ? null
				: env.enclClass.sym);
	}

	public ExecutableElement getEnclosingMethod() {
		return (env.enclMethod == null ? null : env.enclMethod.sym);
	}

	public Iterable<? extends Element> getLocalElements() {
		return env.info.getLocalElements();
	}

	public Env<AttrContext> getEnv() {
		return env;
	}

	public boolean isStarImportScope() {
		return false;
	}

	public boolean equals(Object other) {
		if (other instanceof JavacScope) {
			JavacScope s = (JavacScope) other;
			return (env.equals(s.env) && isStarImportScope() == s
					.isStarImportScope());
		} else
			return false;
	}

	public int hashCode() {
		return env.hashCode() + (isStarImportScope() ? 1 : 0);
	}

	public String toString() {
		return "JavacScope[env=" + env + ",starImport=" + isStarImportScope()
				+ "]";
	}
}
